Question

Related: Correct way to document open-ended argument functions in JSDoc

I’ve a function that accepts multiple arrays by accessing the arguments variable:

/**
 * @param options An object containing options
 * @param [options.bind] blablabla (optional)
 */
function modify_function (options) {
    for (var i=1; i<arguments.length; i++) {
        // ...
    }
}

Now, I know that each argument besides options is an array containing values that are worth documenting:

[search_term, replacement, options]

I’m not considering putting the (lengthy) description in the variable parameter line.

@param {…} An array with search terms, replacements and its options; index 0: the search term within the function; 1: the replacement text; 2: optional options (catch_errors: catches errors and log it, escape: escape dollars in the replacement text, pos: “L” for placing the replacement before the search term, “R” for placing it after)
Not a readable solution and the type is not visible.

Is there a way to document the types and values of a variable parameter?

@param {...[]} An array with search terms, replacements and its options
@param {...[0]} The search term within the function
@param {...[1]} The replacement text 
@param {...[2]} An optional object with obtions for the replacement
@param {...[2].catch_errors} catches errors and log it
@param {...[2].escape} etc...

The above looks ugly, but it should give you an idea of what I’m trying to achieve:

• document the type of a variable parameter (in this case an Array)
• document the values of this array
• document the properties of an object inside this array

For laziness, I’ve used an array instead of a object. Other suggestions are always welcome.

Answer 1

Your function is not truly variable arguments, you should just change its signature to what foundrama suggested. Except that JSDoc has syntax a little better than foundrama suggested

/**
 * @param {String} searchTerm
 * @param {String} replacementText
 * @param {Object} opts (optional) An object containing the replacement options
 * @param {Function} opts.catch_errors Description text
 * @param {Event} opts.catch_errors.e The name of the first parameter 
 *         passed to catch_errors
 * @param {Type} opts.escape Description of options
 */

And you’d call it like

modify_text('search', 'replacement', {
    catch_errors: function(e) {

    },
    escape: 'someEscape'

});

If you really do have a case for varargs style, it should be a variable of the same type that can be passed at the end of the parameter list, I document it like the following, though it’s not a JSDoc standard, it’s what Google uses with their documentation

/**
 * Sums its parameters
 * @param {...number} var_args Numbers to be added together
 * @return number
 */
function sum(/* num, num, ... */) { 
    var sum = 0;
    for (var i =0; i < arguments.length; i++) {
      sum += arguments[i];
    }
    return sum;
}